Am I right on these three?
2 answers:
You might be interested in
Answer:
The frequency of the piano string is <em>1059 Hz</em>.
Explanation:
The frequency beat (fb), 2 beats/second, is the absolute difference between the frequency of the tuning fork (1056 Hz) and the frequency of the piano string.
As the piano string gets tightened, the frequency beat becomes 3 beats/second.
Therefore,
fb =
Answer:
You will need 450 cells (3 cm each) to meet the voltage/current requirement.
The panel must be 3 cells in one side, by 150 cell in another side. 1350 cm^2 or 0.135 m^2. They must be connected 3 in row in parallel (to add current), then each of the former group must be connected in series to meet the voltage, so it would be 150 rows of connected in series.
The panel can be optimized using a voltage inverter, to convert current to voltage. In this way, less cells can be used achieving the same output specs.
Explanation:
To meet the voltage:
120 [v] required voltage
0.8 [v] voltage of each cell
So we need 150 cells in series for the voltage.
To meet the current
1.0 [A] Required current
350[mA]=0.35[A] cell current
1/0.35=3 cell So we need 3 cells in parallel to add the currents and meet the requirement.
See the attached figure
Answer:
h =220 m
Explanation:
Given that
u = 7 m/s
Even mass will attach but this will not produce any effect on the maximum height of the ball.Because in energy conservation the effect of mass does not present.
So the final speed of the ball will be zero at the maximum height.
v² = u² - 2 g (25 + h)
0 = 7² - 2 x 10 (25 +h)
49 = 20 ( 25 +h)
49 = 500 +20 h
Here h comes out negative that is why we are taking the 70 m/s in place of 7 m/s.
0 = 70² - 2 x 10 (25 +h) ( take g =10 m/s²)
4900 = 20 ( 25 +h)
4900 = 500 +20 h
4900- 500 = 20 h
4400 = 20 h
440 = 2 h
h =220 m
